[Application of deep inferior epigastric perforator flap for repair of extreme defects around knee].

[OBJECTIVE] To investigate the effectiveness of the deep inferior epigastric perforator (DIEP) flap for extreme defects around the knee.

[METHODS] Between June 2017 and December 2018, 15 patients with the extreme defects around the knee were admitted. There were 9 males and 6 females with a median age of 36 years (range, 23-51 years). The etiology was the traffic accident in 7 cases, tumor in 5 cases, and burn in 3 cases. The injured location was left knee in 8 cases and right knee in 7 cases. The size of soft tissue defects ranged from 15 cm×10 cm to 30 cm×20 cm, and all defects complicated with exposure of blood vessels, nerves, tendons, and other tissues. Transverse DIEP flaps with 1-2 vascular pedicles were prepared according to the size of the defect, including 6 cases of single-pedicle flaps and 9 cases of double-pedicle conjoined flaps. According to the depth of the defect, 10 cases of skin flaps were thinned under microscope. The size of the DIEP flaps ranged from 16 cm×10 cm to 32 cm×20 cm; the average thickness was 1.5 cm (range, 0.8-1.8 cm); the average pedicle length was 7.5 cm (range, 5.0-9.0 cm). The donor site was directly sutured.

[RESULTS] One single-pedicle flap developed distal necrosis after operation, and healed after skin grafting; the other skin flaps survived, and the wounds at the donor and recipient sites healed by first intention. All patients were followed up 16-28 months (mean, 24 months). The shape and texture of the flap were satisfactory, and there was no abnormal hair growth or obvious pigmentation. There was only linear scar at the donor site and no complication such as abdominal hernia. The appearance and function of the knee were satisfactory. No recurred tumor was observed, and the scar contracture was released. At last follow-up, 13 cases were excellent and 2 cases were good, according to the Knee Society Score (KSS) criteria.

[CONCLUSION] The DIEP flap is an ideal alternative for repairing the extreme defects around knee, with a concealed donor site, easy dissection, flexible design, as well as less complication.